The present invention relates generally to guidance and targeting systems such as may be utilized with air-conveyed weapons, such as missiles and glide bombs, etc.; and more specifically relates to guidance and targeting systems utilizing imaging sensors in such weapons to identify targets and to be used in guiding the weapon toward the target.
Many conventional weapon guidance and targeting systems are utilized to acquire specific targets, and to guide the missile or other weapon to the specific, identified, fixed target. These conventional systems use some type of imaging sensor, such as a passive infrared, MMW, TV, SAR, or CO.sub.2 laser radar (LADAR) sensor. Each of these conventional systems requires that for any specific target, a target reference be prepared. Conventional target reference preparation typically requires the generation of a three dimensional image or model of the target, and may further require the identification of materials for objects and surfaces presented in the three dimensional reference image. This target reference image is then loaded on board the missile to provide a reference for comparison with data sensed by the imaging sensor.
As will be readily appreciated, the difficulty of preparing these target reference models may often make the process extremely time consuming, potentially taking hours and even days of preparation. In many tactical scenarios, this preparation time, and accordingly relatively low response time to changing situations, can present a serious tactical or strategic problem. Another problem, apparent from the discussion above, is that reconnaissance must not only obtain sufficient visual data to facilitate generation of the reference model, but must also provide information regarding materials and stereo pair information to facilitate the three dimensional modeling. Otherwise, the model would contain errors making guidance inaccurate.
Once the basic three dimensional model is created based upon the reconnaissance data, additional complex modeling must be applied to predict IR, MMW, and/or SAR signatures to provide the target reference model to be utilized by the weapon during attack. Once the three dimensional reference model is established, and attack geometry for the weapon is selected, a target reference file is generated for loading into the weapon. This target reference file is frequently an edge map modeled after the edge signatures predicted to be viewed by the particular imaging sensor of the missile. During an attack, the target reference file will be compared to the sensed image to determine when the target has been located and to provide guidance information to the missile guidance system.
As noted above, a significant problem with conventional systems is the requirement that a three dimensional target reference model be prepared in order to establish a target reference file for use on the missile. Additionally, the complexity of the modeling, involving the prediction of signatures which would be recognized by the involved sensor, based upon the reconnaissance data, is significant. Additionally, conventional systems have typically been relatively constrained to attack from the reconnaissance sensor viewing direction, severely limiting tactical options.
Accordingly, the present invention provides a new method and apparatus for guiding and targeting a weapon where a three dimensional imaging sensor may be utilized to provide target recognition without the requirement of the preparation of three dimensional models, thereby optimizing and simplifying mission planning and preparation operations.